A whole-life approach to the development of high integrity welding technologies for Generation IV fast reactors
Lead Research Organisation:
University of Manchester
Department Name: Mechanical Aerospace and Civil Eng
Abstract
"Weld modelling" is a powerful tool in understanding the structural performance of welded structures. Conventional continuum-mechanics-based predictions of the stresses generated by welding have achieved considerable success in understanding the in-service performance and degradation mechanisms of welds in the UK's nuclear reactor fleet. However their practical use is currently limited to materials that do not undergo so-called solid state phase transformation (SSPT) during welding, since the presence of SSPT makes it necessary to predict changes in the material microstructure in order to predict the stresses. In addition, the microstructural changes imposed by welding have a profound influence on a weld's resistance to creep, thermal ageing, oxidation, stress corrosion and other in-service degradation mechanisms, and upon its sensitivity to the presence of cracking.
The Fellowship research programme aims to extend conventional weld modelling into a multi-disciplinary tool that can predict both continuum parameters such as stress & distortion, and microstructural parameters such as grain size and shape, the occurrence of secondary phases, and precipitate distributions, and hence both directly predict long term structural performance and be used for "virtual prototyping " of weld processes and procedures for novel welding processes. Success offers the prospect of better understanding of in-service performance of welds in both the existing UK nuclear reactor fleet, and in any industrial sector where the long term structural performance of welds is important. It will also aid the choice of weldment materials, joint design and welding process for structural welds in new-build nuclear power plants, and in advanced Generation IV designs that may be built on a longer time frame.
The Fellowship research programme aims to extend conventional weld modelling into a multi-disciplinary tool that can predict both continuum parameters such as stress & distortion, and microstructural parameters such as grain size and shape, the occurrence of secondary phases, and precipitate distributions, and hence both directly predict long term structural performance and be used for "virtual prototyping " of weld processes and procedures for novel welding processes. Success offers the prospect of better understanding of in-service performance of welds in both the existing UK nuclear reactor fleet, and in any industrial sector where the long term structural performance of welds is important. It will also aid the choice of weldment materials, joint design and welding process for structural welds in new-build nuclear power plants, and in advanced Generation IV designs that may be built on a longer time frame.
Planned Impact
Potential Beneficiaries include:
1) Operators of existing plant in the nuclear, conventional power generation and offshore energy extraction sectors
2) Fabricators and potential fabricators of high integrity weldments, in the same industry sectors
3) The UK as a whole, via its potential impact on life extension of the existing nuclear fleet.
4) Researchers in the field of weld structural performance, especially those working on potential structural weld designs and materials for high temperature Gen IV reactor designs
The primary outputs of the Fellowship will be reliable, fully validated techniques for the prediction of weld thermal histories, residual stresses, inelastic strains and distortions in steels and nickel alloys, with and without solid state phase transformation, in a large variety of weld types; demonstration of the feasibility and utility of coupling microstructural prediction with conventional finite element weld modeling in AISI 316L; and techniques for coupling weld modeling with direct damage prediction in cracked structures.
This research will benefit both those who need to better understand and predict the in-service structural performance of weldments, and those who need to optimise weld processes, joint design and material choice and so will benefit from "virtual prototyping" and modelling insight into the potential service consequences of weld design and fabrication decisions. This includes all the groups identified above.
1) Operators of existing plant in the nuclear, conventional power generation and offshore energy extraction sectors
2) Fabricators and potential fabricators of high integrity weldments, in the same industry sectors
3) The UK as a whole, via its potential impact on life extension of the existing nuclear fleet.
4) Researchers in the field of weld structural performance, especially those working on potential structural weld designs and materials for high temperature Gen IV reactor designs
The primary outputs of the Fellowship will be reliable, fully validated techniques for the prediction of weld thermal histories, residual stresses, inelastic strains and distortions in steels and nickel alloys, with and without solid state phase transformation, in a large variety of weld types; demonstration of the feasibility and utility of coupling microstructural prediction with conventional finite element weld modeling in AISI 316L; and techniques for coupling weld modeling with direct damage prediction in cracked structures.
This research will benefit both those who need to better understand and predict the in-service structural performance of weldments, and those who need to optimise weld processes, joint design and material choice and so will benefit from "virtual prototyping" and modelling insight into the potential service consequences of weld design and fabrication decisions. This includes all the groups identified above.
Organisations
- University of Manchester (Fellow, Lead Research Organisation)
- NUCLEAR ADVANCED MANUFACTURING RESEARCH CENTRE (Collaboration)
- EDF Energy (United Kingdom) (Collaboration, Project Partner)
- European Commission (Collaboration)
- University of Bristol (Collaboration)
- Australian Nuclear Science and Technology Organisation (Project Partner)
- Rolls-Royce (United Kingdom) (Project Partner)
People |
ORCID iD |
Michael Smith (Principal Investigator / Fellow) |
Publications
Vasileiou A
(2019)
Residual stresses in arc and electron-beam welds in 130 mm thick SA508 steel: Part 2 -measurements
in International Journal of Pressure Vessels and Piping
Smith M
(2019)
Validated prediction of weld residual stresses in austenitic steel pipe girth welds before and after thermal ageing, part 1: Mock-up manufacture, residual stress measurements, and materials characterisation
in International Journal of Pressure Vessels and Piping
Xiong Q
(2019)
Validated prediction of weld residual stresses in austenitic steel pipe girth welds before and after thermal ageing, part 2: Modelling and validation
in International Journal of Pressure Vessels and Piping
Smith M
(2018)
Optimised modelling of AISI 316L(N) material behaviour in the NeT TG4 international weld simulation and measurement benchmark
in International Journal of Pressure Vessels and Piping
Smith M
(2018)
Advances in weld residual stress prediction: A review of the NeT TG4 simulation round robins part 2, mechanical analyses
in International Journal of Pressure Vessels and Piping
Smith M
(2018)
The NeT Task Group 4 residual stress measurement and analysis round robin on a three-pass slot-welded plate specimen
in International Journal of Pressure Vessels and Piping
Balakrishnan J
(2018)
Residual stress distributions in arc, laser and electron-beam welds in 30 mm thick SA508 steel: A cross-process comparison
in International Journal of Pressure Vessels and Piping
Sun Y
(2022)
Assessing and mitigating the distortion and stress during electron beam welding of a large shell-flange structure
in International Journal of Pressure Vessels and Piping
Smith M
(2018)
Advances in weld residual stress prediction: A review of the NeT TG4 simulation round robin part 1, thermal analyses
in International Journal of Pressure Vessels and Piping
Sun Y
(2020)
Effects of dilution on the hardness and residual stresses in multipass steel weldments
in International Journal of Pressure Vessels and Piping
Description | The award focussed upon developing simulation methods for weld process / material combinations used in current and next generation reactors. We focussed on predicting residual stresses, and validating those predictions against a wide variety of measurement techniques. For austenitic stainless steels such as AISI 316, we now have a very good understanding of the key variables controlling accurate prediction and measurement of weld residual stresses, and significant insight into the real world variability of both measurement and simulation techniques. We have undertaken a similar exercise for nickel alloy welds, again collaborating internationally via the NeT network. There still remain unanswered questions about material behaviour in these systems, but significant progress has been made. We have worked extensively on low alloy pressure vessel steels, where "solid state phase transformation" has the capacity to affect residual stress development. This mess-scale process has been incorporated into continuum finite element modelling, and we are developing a good understanding of when it is necessary to consider its effects. |
Exploitation Route | WE are seeking to embody what has been learned into the R6 structural integrity assessment procedure, which is extensively used in high value safety critical industries in the UK, where the knowledge may be accessed and applied by industry practitioners. We have also used the outcomes to participate in two projects (to date) in the BEIS Nuclear Innovation programme, working in collaboration with Industry leads, in Phase 1 (MATTEAR, led by Jacobs (then Wood)), and phase 2 led by SFEL) |
Sectors | Energy,Manufacturing, including Industrial Biotechology |
Description | They have fed into the BEIS nuclear Innovation programme via our participation in tow projects: MATTEAR, led by Wood Group (now Jacobs), and Industrialisation of large scale electron beam welding for the nuclear industry, led by Sheffield Forgemasters. We are also using outputs in the SINDRI Prosperity Partnership between EDF (industry) and Bristol, Manchester and Imperial (academia) |
First Year Of Impact | 2018 |
Sector | Energy,Manufacturing, including Industrial Biotechology |
Impact Types | Economic |
Description | EPSRC Design by Science Funding call |
Amount | £1,003,550 (GBP) |
Funding ID | EP/P005284/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 12/2016 |
End | 11/2019 |
Description | Euratom Fission 2016-2017 Call NFRP-2016-2017 - ATLAS+ project |
Amount | € 3,930,864 (EUR) |
Organisation | European Commission |
Sector | Public |
Country | European Union (EU) |
Start | 05/2017 |
End | 04/2021 |
Title | Data supporting: 'Assessing and mitigating the distortion and stress during electron beam welding of a large shell-flange structure' |
Description | Fig. 7. (c) temperature histories on the outer surface points (i.e., Out1 and Out2) and inner surface points (i.e., In1 and In2). Fig. 8. (d) The cross-weld line profile of hardness distribution. Fig. 10. Evolution of the opening (a) and sliding (b) displacements for mid-thickness locations on the weld plane with different angular distances to the EB weld start position. |
Type Of Material | Database/Collection of data |
Year Produced | 2022 |
Provided To Others? | Yes |
URL | https://cord.cranfield.ac.uk/articles/dataset/Dataset_for_Assessing_and_mitigating_the_distortion_an... |
Description | EDF Modelling and Simulation Centre (MaSC) |
Organisation | EDF Energy |
Country | United Kingdom |
Sector | Private |
PI Contribution | I am MaSC director. My team contributes research in Welding technology to the partnership |
Collaborator Contribution | EDF second ~10 permanent and short term employees to the University to work within the research themes of MaSC, and provide direct financial support to myself, the Centre administrator, and PDRA's working in MaSC themes |
Impact | To be added later |
Start Year | 2015 |
Description | European Network on Neutron Techniques Standardization for Structural Integrity (NeT) |
Organisation | EDF Energy |
Department | EDF Innovation and Research |
Country | France |
Sector | Private |
PI Contribution | Leadership of task groups, contributions to all stages of the research involved |
Collaborator Contribution | See the URL. Varies with project |
Impact | This is a multi-disciplinary collaboration with up to 30 organisations involved, although the numbers vary with the project See URL for details |
Start Year | 2007 |
Description | European Network on Neutron Techniques Standardization for Structural Integrity (NeT) |
Organisation | European Commission |
Department | Joint Research Centre (JRC) |
Country | European Union (EU) |
Sector | Public |
PI Contribution | Leadership of task groups, contributions to all stages of the research involved |
Collaborator Contribution | See the URL. Varies with project |
Impact | This is a multi-disciplinary collaboration with up to 30 organisations involved, although the numbers vary with the project See URL for details |
Start Year | 2007 |
Description | European Network on Neutron Techniques Standardization for Structural Integrity (NeT) |
Organisation | University of Bristol |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Leadership of task groups, contributions to all stages of the research involved |
Collaborator Contribution | See the URL. Varies with project |
Impact | This is a multi-disciplinary collaboration with up to 30 organisations involved, although the numbers vary with the project See URL for details |
Start Year | 2007 |
Description | Nuclear Advanced Manufacturing Research Centre |
Organisation | Nuclear Advanced Manufacturing Research Centre |
Country | United Kingdom |
Sector | Charity/Non Profit |
PI Contribution | I chair the NAMRC Research Borad, which manages its internal and member-financed research programme My researchers have delivered fundamental multi-component CFD analyses of high energy keyhole welds to aid in process optimisation and the minimisation of weld defects, and conventional FE analysis of large EB-welded structures to aid in designing welding restraint systems to prevent distortion induced manufacturing failures |
Collaborator Contribution | Supply of materials Welding of specimens Funding for simulation activities: Fundamental multi-compose nt CFD of weld keyholes, and more conventional FE analysis of manufacturing distortion in large EB welded structures |
Impact | Confidential reporting to the NAMRC of the simulation campaigns listed above |
Start Year | 2016 |
Description | Residual stress modelling training workshop |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Workshop on residual stress modelling in welded structures - funded as part of the ATLAS+ project |
Year(s) Of Engagement Activity | 2021 |